Control valve with integral streamlined seating means

Abstract

A streamlined control valve with integral seating means having a flow characteristic determining contour and being part of a gradually expanding flow path formed between said contour and a movable central valve plug with a streamlined contour facing an orifice and being designed to have an abrupt area change producing configuration on its discharge side.

I claim: 
     
       1. Control valve with integral seating means and movable plug means capable of generating together low fluid flow resistant passages at the maximum retraction of said plug means from said sealing means and a turbulence and higher fluid resistant producing throttling path at lesser distances of said plug from said seating means, comprising: (a) a valve housing having inlet and outlet ports and a central reduced diameter orifice having a longitudinal axis which is located perpendicular to the axis of the inlet or outlet port, streamlined flow passages with interior wall surfaces having gradually expanding cross sectional areas connecting said reduced diameter orifice to either the inlet or outlet port, said valve housing further incorporating a perpendicular access opening located concentric to said orifice;   (b) a beveled surface constituting seating means located at the upper terminating plane and extending diametrically outwards from said orifice;   (c) a contoured wall portion extending both vertically upwards and radially outwards from said seating surface and terminating within one of said flow passages;   (d) a movable valve plug having an outer beveled seating surface complementary to that of the orifice and lower curved wall surfaces designed to generate a nearly constant velocity profile of fluid passing from said orifice and between said contoured wall portion on one side and said curved wall surfaces of the plug when the latter is fully retracted from said orifice, said plug further having a flat terminating upper surface located slightly above said beveled seating surface to provide a sharp discontinuity for fluid flow along said curved wall surfaces;   (e) bonnet means suitably retained within said perpendicular access opening of the housing and having a lower circular portion with a central opening containing within guiding means capable of slidingly engaging a valve stem whose lower terminating end is fastened to said valve plug, the lower circular portion of the bonnet furthermore having a flat terminating surface complementary and essentially identical to the upper terminating end of the valve plug to provide continuous fluid guiding when the plug is fully retracted.   
     
     
       2. Control valve with integral seating means according to claim 1, wherein said contoured wall portions extending from said orifice are designed to provide a mathematically definable area and flow rate increase in conjunction with the terminating upper surface of said movable valve plug. 
     
     
       3. Control valve with integral seating means according to claim 1, wherein the lower circular portion of said bonnet means extends within the flow passage connecting said orifice with the outlet port, and wherein said circular portion has a profiled indenture designed to provide a near constant velocity profile for the fluid passing from said orifice and between the profiled indenture and the wall surface of said flow passage.